N-polythiodimorpholines have found utility in the rubber industry as sulfur donors and vulcanization accelerators. Previous methods to prepare N-polythiodimorpholines have included adding sulfur to a solution of morpholine disulfide. The problem with this preparation is that the preparation of morpholine disulfide is expensive and cumbersome. Morpholine disulfide is prepared by the reaction of morpholine and sulfur monochloride in the presence of alkali in an organic solvent. M. C. Throdahl and M. W. Harman, Ind. Eng. Chem., 43, 421 (1951).
Another prior art methodology for the preparation of N-polythiodimorpholines involves the use of halopolysulfides and morpholine. This procedure uses the highly toxic and corrosive halopolysulfides, for example, chlorodisulfide and dichloropolysulfides.
There is a need in the rubber chemical industry for a new process that efficiently and economically produces N-polythiodimorpholines which does not require the use of expensive or dangerous starting materials.